Temporal Cavity Solitons in Passive Kerr Resonators: Experimental Studies on Dynamical Behaviours

Abstract

In this Thesis, we present a series of theoretical and experimental investigations on the nature and behaviour of temporal cavity solitons in a high finesse macroscopic optical fiber resonator. Our first investigation is on the theme of collision interactions between two solitons. Through numerical simulations, it is found that there can be several collision outcomes depending on the initial system parameters. We present experimentally observed transient dynamics for two of these outcomes: two solitons colliding to form one soliton, and two solitons colliding to cancel each other completely. Our second investigation looks into the spontaneous creation of temporal cavity solitons by scanning the driving laser over a cavity resonance. Whilst this technique has previously been used to excite cavity solitons in monolithic microresonators, it has not yet been demonstrated in a macroscopic fiber resonator. The results of our first experiment suggest the presence of acoustic effects arising from stimulated Brillouin Scattering, which we then suppress in a follow-up experiment by using a sinusoidal phase modulation to broaden the pump spectrum. The results from this experiment show clear evidence of the spontaneous formation and annihilation of temporal cavity solitons during the laser scan. Due to the large roundtrip time of our resonator, we are able to experimentally capture the soliton formation dynamics in real time. Finally, our last investigation examines the dynamics of breathing temporal cavity solitons. Simulations reveal that for large driving powers, there is a certain range of cavity phase detunings for which cavity solitons have an oscillatory (\breathing") nature. In this investigation, we present the first experimental observation of the real-time spectral evolution of such solitons, as well as numerical simulations that illustrate how their breathing characteristics depend on the system parameters.